What questions should I ask to assess for obsessive‑compulsive disorder (OCD) in a patient?

How to Assess for OCD in a Patient

Begin your assessment with a detailed psychiatric history and mental status examination, specifically asking about intrusive unwanted thoughts and repetitive behaviors that consume more than 1 hour daily and cause significant distress or functional impairment 1.

Core Diagnostic Questions to Ask

Screen for Obsessions

Ask patients directly about:

• Recurrent, intrusive thoughts, images, or urges that feel unwanted and cause anxiety or distress
• Whether they try to ignore, suppress, or neutralize these thoughts with other thoughts or actions
• Common obsession themes:
  • Contamination fears
  • Concerns about harm to self or others
  • Intrusive aggressive or sexual thoughts
  • Need for symmetry or exactness 1

Screen for Compulsions

Inquire about:

• Repetitive behaviors (hand washing, checking, ordering) or mental acts (counting, praying, repeating words silently)
• Whether these behaviors feel driven or mandatory in response to obsessions or rigid rules
• Whether these actions are aimed at preventing anxiety or a dreaded event, even if not realistically connected 1

Assess Time and Impairment

Critical threshold questions:

• "Do these thoughts and behaviors take up more than 1 hour per day?"
• "Do they cause significant distress or interfere with work, relationships, or daily activities?"

This time/impairment criterion distinguishes OCD from normal intrusive thoughts that occur in the general population 1.

Assess Insight Level

Ask patients how strongly they believe their OCD concerns are true. This determines the DSM-5 insight specifier 1:

• Good/fair insight: Patient recognizes beliefs are probably not true
• Poor insight: Patient thinks beliefs are probably true
• Absent insight/delusional: Patient is completely convinced beliefs are true

Clinical pitfall: Patients with absent insight may be misdiagnosed with psychosis rather than OCD, leading to inappropriate treatment 1.

Screen for Tic Disorders

Specifically ask about current or past tics (motor or vocal), as the DSM-5 tic specifier indicates different phenomenology and treatment considerations. Males with early-onset OCD (before puberty) are more likely to have comorbid tics 1.

Rule Out Differential Diagnoses

Distinguish from other conditions by asking:

• Generalized anxiety/depression: Are worries about real-life concerns rather than irrational obsessions? Are compulsions absent? 1
• Other OCRDs: Is the focus specifically on appearance (body dysmorphic disorder), hoarding, hair-pulling, or skin-picking rather than typical OCD themes? 1
• Substance use: Could symptoms be due to drugs or medications? 1

Structured Assessment Tools

For systematic evaluation, consider using 1:

Diagnostic interviews:

• SCID-5 (Structured Clinical Interview for DSM-5) - adults
• ADIS-5 (Anxiety Disorders Interview Schedule) - adults and children
• MINI 7.0 (Mini International Neuropsychiatric Interview) - shorter option

Symptom severity measures:

• Y-BOCS (Yale-Brown Obsessive-Compulsive Scale) - most widely used, includes symptom checklist and severity rating
• CY-BOCS (Children's Y-BOCS) - pediatric version
• FOCI (Florida Obsessive-Compulsive Inventory) - shorter alternative with 5-item severity scale

Additional Assessment Areas

Family accommodation: Ask family members if they provide reassurance, assist with avoidance, or participate in rituals, as this maintains symptoms 1.

Functional impairment: Assess specific impacts on work, school, relationships, and self-care 1.

Comorbidities: Screen for depression, other anxiety disorders, tic disorders, and other OCRDs, which are common 1.

Key Clinical Caveats

• Children may have difficulty identifying or describing obsessions, so focus more on observable compulsions 1
• Avoidance behaviors are a key but often overlooked feature - ask what situations or activities patients avoid to prevent triggering obsessions 1
• Early-onset OCD (before puberty) is more common in males and often associated with tics 1
• Consider PANDAS (pediatric autoimmune neuropsychiatric disorders associated with Streptococcus) in children with sudden onset of symptoms following streptococcal infection 1